Hi all, I already posted this on the technical 2.5L forum at Vortex but I thought I might as well ask here too just in case. Don't usually like to post if I can help it but on this certain topic I'm hard pressed to find specific information on my problem.
My 07 Rabbit has just now about 127k on the clock, and I've owned it for nearly two years. A couple of months ago, I decided to install an Injen CAI just to add some noise and hp (plus my stock box was missing the connector hose that goes to the front grille so I took the opportunity to upgrade). However, ever since that day, I've been getting some horrible suction noise on every cold startup without failure. Fortunately, I have witnessed no fault codes that could be related to the issue since the issue has come about, and the car still runs as good as it ever did on the stock intake box. I should also mention that if I just ignore the cold start up and put the car into gear the noise does not occur. It happens at a specific RPM during cold startup every time.
Since I've been scratching my head about this for awhile now, today I decided to get the occurrence on video and ask around for help. It happens at 0:24. Here's the link:
Now, here's my two running theories.
My 07 Rabbit has just now about 127k on the clock, and I've owned it for nearly two years. A couple of months ago, I decided to install an Injen CAI just to add some noise and hp (plus my stock box was missing the connector hose that goes to the front grille so I took the opportunity to upgrade). However, ever since that day, I've been getting some horrible suction noise on every cold startup without failure. Fortunately, I have witnessed no fault codes that could be related to the issue since the issue has come about, and the car still runs as good as it ever did on the stock intake box. I should also mention that if I just ignore the cold start up and put the car into gear the noise does not occur. It happens at a specific RPM during cold startup every time.
Since I've been scratching my head about this for awhile now, today I decided to get the occurrence on video and ask around for help. It happens at 0:24. Here's the link:
Now, here's my two running theories.
- Right now I'm getting a vacuum leak from the pump that's gone bad, which I haven't gotten around to fixing yet. I feel like that ones a stretch just because if it truly was a symptom for such a common issue for this engine I would have seen somebody else talk about it by now. Also, while the leak did start around the same time as I installed the CAI, I'm doubtful of the coincidence. Either way I have the delete kit already so that will be fixed in the coming days.
- My other theory is that it could be the secondary air injection hose -- when I was installing the CAI, I wasn't able to get the secondary air injection hose FULLY seated. It's inserted enough where it has not slipped out or anything like that, but regardless, it's not fully seated. No matter how hard I try to force the hose to latch on, it just doesn't. Don't know if it's because the port on the CAI is rough/inaccurately machined or because from where the CAI is the hose doesn't have enough slack. Either way, this could be the no brainer solution to my problem but I don't have enough confidence that it is. Here's a link to some photos of what I'm talking about:
